284 THE AMERICAN NATURALIST. 
black center is first pasted upon a manilla board with good 
library paste, and then the board is attached to the tablet by 
simply gumming the edges with a thin solution of Le Page's 
glue poisoned with corrosive sublimate to keep insects away. 
At this point the tablet must be placed under a press to dry, 
in order to avoid warping. The writer has used thin sheets of 
lead for this purpose, which have been very successful. 
After drying for three or four hours the tablet is ready for 
the labels and specimens ; the former being printed upon the 
same stock as the tablet cover, and attached by putting a few 
drops of glue upon the ends and in the middle, and placed 
under a press for an hour or so. For order, class, family, etc., 
a tablet 3 x 1 inch has been adopted and the printed label 
glued to it. For genera a tablet 3 x % inch has been found 
desirable. The tablets have been graded in the following 
sizes, the unit width being three inches : 3 X 2, 3X 4, 3X6, 
3X9, 6x6, 9X9. These sizes will accommodate any speci- 
mens save those which should be placed in special upright 
cases. The larger tablets, 6 x 6 and 9 x 9, will need to have a 
piece of heavy paper pasted on the reverse side, to keep them 
from warping. The specimens are attached to the tablets with 
Le Page's glue. 
The expense of these tablets will not exceed one and a half 
cents each, and several hundred can be manufactured in a day. 
A case installed in this manner presents a handsome appear- 
ance and greatly increases the facility for examination. 
It has been urged by some that the tray is better adapted 
to museum purposes than the tablet, on account of the danger 
of mixing species. In answer to this the writer would say 
that the collections of the Chicago Academy of Sciences have 
been mounted upon tablets for the past six years, and up to 
the present time no mixing has taken place. Of course care 
must be used, with the tray equally as with the tablets, to 
guard against accidents. The new tablet spoken of above has 
been in use in the institution mentioned for the past five 
months. 
